Merge pull request #5 from kowalgta/master

PayPal DoExpressCheckoutPayment now accepts full order details so invoices are populated correctly
Bump version for PayPal DoExpressCheckoutPayment feature
Shayne's no warning changes
Added card types and luhn check utility
Card utility for partial card number and card types
Added multiple currency support
Merge pull request #7 from stephenlacy/master

Added Multiple Currency Support
Make GBP default currency - failing integration tests
New API includes currency code
Replace SystemTime with ITimeProvider
Multiple Currency Support fix

The get checkout details was returning the default enum, I updated it so
that it returns the correct value.
Added test for GetExpressCheckoutDetails

Added a test for GetExpressCheckoutDetails to ensure it parses the
currency code and adds it to the order detail
Add MerchantId to DataCash3DSecureGateway

Paul Owens fix for eSpares case 16748 merged from Kiln
Merge pull request #9 from stephenlacy/MultiCurrencyOnly

Fix to parse back CurrencyCodeType in response
Added Refunds for PayPal
Added amount fields to Paypal Refund response
Merge pull request #12 from brooklynDev/master

Added Refunds to PayPal
Add support for optional fields on SetExpressCheckout call
Merge pull request #13 from jbeke/master

Added support for optional fields on the PayPal SetExpressCheckout call
Ability to refund existing DataCash transactions